Today people routinely separate whole blood by centrifugation into its various therapeutic components, such as red blood cells, platelets, and plasma.
Conventional blood processing methods use durable centrifuge equipment in association with single use, sterile processing systems, typically made of plastic. The operator loads the disposable systems upon the centrifuge before processing and removes them afterwards.
Conventional automated blood processing methods typically entail a range of different fluid flow rates. Relatively high flow rates are required to circulate blood during processing, as well as to circulate ancillary fluids for priming before use and rinsing after use. On the other hand, relatively low flow rates are required to supply anticoagulant.
One approach is to provide dedicated pumps, some to meet high flow volume requirements, and others to meet low flow volume requirements.
The approach that the invention takes is different. A principal objective of the invention is to meet both high and low flow requirements with a single pump.